import cv2 as cv


def main():
    img = cv.imread('../data/sudoku.png', 0)
    img = cv.medianBlur(img, 5)
    ret, thresh = cv.threshold(img, 60, 255, cv.THRESH_BINARY_INV)
    cv.imshow('img', img)
    cv.imshow('thresh', thresh)
    cv.waitKey(0)
    cv.destroyAllWindows()


if __name__ == "__main__":
    main()
